Diode plate construction



Get. 29, 1957 e. L. RISHELL DIODE PLATE CONSTRUCTION 2 Sheets-Sheet 1Filed April 16, 1953 I III! I I I I INVENTOR 650/365 L R/SHHI.

BY W

ATTOR Oct. 29, 1957 G. L. RISHELL 2,811,662

DIODE PLATE CONSTRUCTION Filed April 16, 1953 2 Sheets-Sheet 2 INVENTOR650/265 L. R/SHELL ATTORNEY United States Patent DIODE PLATECONSTRUCTION George L. Rishell, Emporium, Pa., assignor to SylvaniaElectric Products Inc., a corporation of Massachusetts Application April16, 1953, Serial No. 349,215

3 Claims. c1. 313--261) This invention relates to tube construction andto diode plates therefor.

t is an object of the invention to provide a construction so as tocheapen the cost of production of a radio tube, at the same timeproviding better electrical connection of parts.

In particular it relates to multipurpose radio tubes utilizing a diodeconstruction. In such tubes it is usual to provide a common cathode forthe various sections of the tube and to associate the diode plate orplates with the lower portion of the cathode. The upper portion of thecathode may be associated with other elements to form an amplifyingsection of the tube as for example in tube types 6SQ7, 12AT6, and 12A7although for the purpose of illustration type 7E6 has been chosen. Thisis a duo-diode-triode.

In tubes of this character, it has been the practice to mount the diodeplates or anodes by the use of jigs in order to obtain alignment and touse intermediate support wires or connectors which may also require jigmounting. By the construction hereinafter set forth, the use of jigs isobviated since the anodes may be easily mounted on one of the micaspacers provided in the tube, thereby efiecting saving of considerableexpense and also insuring accurate positioning of the anodes.Furthermore, due to the configuration of the anodes and theirpositioning with relation to the wire leads which extend through thebase of the tube, simplification of manufacture and sturdierconstruction of the tube is obtained.

For a full understanding of my invention attention is directed to theaccompanying drawing in which:

Fig. l is a basing diagram of the tube.

Fig. 2 is an elevational view of the elements in the tube, the tubeenvelope being shown partly in section and broken away, the outer basebeing removed.

Fig. 3 is a section through the tube on the line 33 thereof, thefilament leads and other portions below the mica being shown in dottedlines.

Fig. 4 is a top perspective view of the diode section of the tube, partsbeing broken away.

Fig. 5 is a section through the diode portion of the tube in the line5-5 of Fig. 3.

Fig. 6 is a plan view of a mica spacer serving to support and suitablyspace some of the electrodes, and

Fig. 7 is a fragmental perspective view of a modified form of attachmentof the diodes to the Wire leads and a modified shield.

Referring to the figures more in detail, the reference character 10indicates a glass envelope having cup portion 12 through an annularportion of which extend the wire leads or pins indicated as 14 with asubscript corresponding to the electrode identifying numerals in Fig. 1.Forming a part of the electrode support are support rods 16, these rodshaving angularly turned lower ends 18 welded to the pins 144 and 147.The top ends of all of pins 14 extend above the level of the bent iceends 18 of the support rods. Threaded over the support rods and over thepins is a preperforated mica disc 20, the perforations thereinregistering with the pins and rods. The disc rests on the bent ends 18of the rods. There is also a central perforation in the disc for thesnug accommodation of a cathode 22. Mounted on the mica 20 is a pair ofdiode plates 24-. Each diode plate when developed is generallyrectangular in form. As shown in use it is of stepped formationcomprising two parallel offset risers 26 and 28, joined by a tread 30.Each riser 28 has substantially semi-cylindrical concave portion 32adapted to partially surround the lower end of the cathode in closelyspaced relation thereto to form a plate of a diode. Formed on the loweredge of riser 26 and the lower edge of tread 3d are ears 32' adapted topass through perforations in the mica 20 and be bent thereagainst. Inlieu of the ears 32' on the tread or in addition thereto, ears may beprovided on the riser 28. These ears serve to firmly hold the diodeplates in proper position relative to the cathode. In order that theplates may be used interchangeably as either a right or a left diodeplate and to enable one die to serve in making both plates, a second setof ears 34 is stamped out on the plates. These ears, preferably for thesake of symmetry of parts are arranged directly opposite to each other.These diode plates are welded directly to the pins and 14a either byreason of the pins being welded to sides of the risers 26, as shown inFig. 4, or by reason of the lower projections 32' being welded to pinsand 15s, as shown in Fig. 7, these pins being shorter than pins 145 and14s. Surrounding the diode plates and shielding the triode section ofthe tube from the twin diode section is a shield 36 having Wing portions38, reversely bent portions 40, and a boxing-in section comprisingupright end walls 42, a vertical back wall 44 and a deck 46 bent to ahorizontal position from the vertical back Wall. The reversely bentportions at their bights are suitably secured to pins 144 and 147. ifdesired the wing portions 38 and their shielding function may beeliminated, as shown in the form of shield 37 illustrated in Fig. 7,thereby effecting a saving in material. The deck portion has a centralperforation 48 larger in diameter than the coated cathode 22, saidperforation registering with the central opening in the mica 20. The endwalls 42 extend above the deck 46 and are provided with ears 50 tosupport a suitably perforated mica 52 threaded over the rods 16 and overthe ears 50, into engagement with the upper edges of walls 42. The edgeof the mica 52 may be slotted from the edge thereof toward the center,as indicated at 54, to permit assembly of the cathode with the mica 52without injury to the coating at the lower end of the cathode, prior tothreading the mica over the rods 16. As is known in the art, the cathodeis inserted by deflecting one of the Wings of the slot upwardly anddeflecting the other one downwardly to enable the cathode to be insertedat an angle to the plate of the mica; subsequently the cathode ispositioned perpendicularly to the mica surface. The cathode has a bead56 formed thereon to prevent downward displacement of the cathode beyondthe bead position, the bead being slightly larger than the centralperforation in mica 52.

Within the cathode is a filament 58 secured to two tabs 60 weldedrespectively to pins 141 and 14s. Suitably spaced above the mica 52 is asimilar mica 62 and interposed between the micas is the filamentcontaining cathode 22 provided with a second bead'64. Also so interposedis a grid 66 and a plate 68, the grid and plate being provided withextensions, as is common in the art, to pass through the micas, theplate extension being bent more or less thereover as found necessary.

This grid is electrically connected by a grid support tab 76 to pin 143while the plate is connected by a lead 72 to pin 142. This lead is notvisible in Fig. 2 since it is hidden by the cathode and other parts. Thecathode is connected to the cathode pins 144 and 147 by tab 74 connectedto rod 16 which in turn, as set forth above, is connected to said pins.The reference character 76 indicates the getter organization.

The glass envelope is made in two parts, a cup-shaped member in whichthe leads 14 are embedded and a bulb member which after assembly of theelements in the tube is fused onto the cup shaped member. The line ofjuncture is indicated by the dotted line 78 in Fig. 2.

In assembling the parts, the rods 16 are secured to the leads 144 and147 of the cup shaped member after which the lower mica disc 20 isthreaded onto the rods and pins, then the diode plates and shield areslid into place. Next the mid mica 52 with filament loaded cathode 22positioned in the mica is slid over the rods and onto the ears'50 on theshield after which the grid and plate are slipped over the cathode. Theconnecting tabs, leads and getter are then welded in place. Of coursethe shield is also secured to the rods and the ears 32 bent over themica or welded to the pins, as desired. The extensions on the plate arebent over under the micas to attain the desired degree of rigidity ofstructure, or the rods 16 may be swaged adjacent the micas to inhibitmovement of the assembled electrodes. Thus the tube may be assembledwithout the use of jigs and in an expeditious manner. Furthermore, thedual eared construction 32', 34 on the diode plates permits cheapermanufacture of parts since but one set of dies rather than two isnecessary in their manufacture. Since diode pins are conventionallyarranged in proximity to each other, the parallel symmetrical diodeplate arrangement set forth herein allows for direct connection withthese pins Without the use of separate and intermediate tabs. The plateconstruction shown furthermore contributes toward rigidity of parts.

Having thus described my invention, what I claim as new is:

1. An electronic device comprising a header having lead-in wiresextending into the device, a pair of upright support rods having lowerangularly bent ends securely fastened to two of said lead-in wires, aninsulating wafer threaded on said support rods and resting on said bentends, electrode elements having edges abutting the wafer and directlysecured to other lead-in wires;

2. An electronic device comprising a header having lead-in wiresextending into the device, a pair of upright support rods having lowerangularly bent ends securely fastened to two of said lead-in wires, aninsulating wafer threaded on said support rods and resting on said bentends, electrode elements having edges abutting the wafer, other lead-inwires extending through the wafer and directly secured to said electrodeelements.

3. An electronic device comprising a header having lead-in wiresextending into the device, a pair of upright support rods having lowerangularly bent ends securely fastened to two of said lead-in wires, aninsulating wafer threaded on said support rods and resting on said bentends, electrode elements having edges abutting the wafer and havingprojections extending down through and below the wafer, and otherlead-in wires terminating directly below the wafer and secured to saidprojections.

References Cited in the file of this patent UNITED STATES PATENTS1,672,483 Crowley June 5, 1928 2,352,933 Beggs July 4, 1944 2,708,329McKee May 17, 1955 FOREIGN PATENTS 662,433 Great 'Britain Dec. 5, 1951

